$68 Cheap Flights from St. Louis (STL) to Baltimore (BWI)

View $68 flight on Thu, Aug 14, 2025Opens in a new window

Popular airlines from St. Louis Lambert Intl. Airport (STL) to Baltimore Washington Intl. Airport (BWI)

Cheap Flights from St. Louis to Baltimore (STL-BWI)

Prices were available within the past 7 days and start at $68 for one-way flights and $138 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Spirit Airlines
Sun, Oct 5 - Sun, Oct 19
STL
St. Louis
BWI
Baltimore
$138 Roundtrip, found 6 days ago
$138
Roundtrip
found 6 days ago
Select Spirit Airlines flight, departing Sun, Oct 5 from St. Louis to Baltimore, returning Sun, Oct 19, priced at $138 found 6 days ago
Spirit Airlines
Thu, Aug 21 - Mon, Aug 25
STL
St. Louis
BWI
Baltimore
$148 Roundtrip, found 6 days ago
$148
Roundtrip
found 6 days ago
Select Spirit Airlines flight, departing Thu, Aug 21 from St. Louis to Baltimore, returning Mon, Aug 25, priced at $148 found 6 days ago
Spirit Airlines
Sun, Sep 14 - Tue, Sep 16
STL
St. Louis
BWI
Baltimore
$155 Roundtrip, just found
$155
Roundtrip
just found
Select Spirit Airlines flight, departing Sun, Sep 14 from St. Louis to Baltimore, returning Tue, Sep 16, priced at $155 just found
Spirit Airlines
Sun, Sep 7 - Mon, Sep 8
STL
St. Louis
BWI
Baltimore
$155 Roundtrip, found 1 hour ago
$155
Roundtrip
found 1 hour ago
Select Spirit Airlines flight, departing Sun, Sep 7 from St. Louis to Baltimore, returning Mon, Sep 8, priced at $155 found 1 hour ago
Spirit Airlines
Thu, Aug 14 - Thu, Aug 21
STL
St. Louis
BWI
Baltimore
$157 Roundtrip, just found
$157
Roundtrip
just found
Select Spirit Airlines flight, departing Thu, Aug 14 from St. Louis to Baltimore, returning Thu, Aug 21, priced at $157 just found
American Airlines
Tue, Oct 7 - Sun, Oct 12
STL
St. Louis
BWI
Baltimore
$158 Roundtrip, found 18 hours ago
$158
Roundtrip
found 18 hours ago
Select American Airlines flight, departing Tue, Oct 7 from St. Louis to Baltimore, returning Sun, Oct 12, priced at $158 found 18 hours ago
American Airlines
Tue, Oct 21 - Sun, Oct 26
STL
St. Louis
BWI
Baltimore
$159 Roundtrip, found 3 days ago
$159
Roundtrip
found 3 days ago
Select American Airlines flight, departing Tue, Oct 21 from St. Louis to Baltimore, returning Sun, Oct 26, priced at $159 found 3 days ago
Southwest Airlines
Tue, Oct 7 - Sun, Oct 12
STL
St. Louis
BWI
Baltimore
$160 Roundtrip, found 18 hours ago
$160
Roundtrip
found 18 hours ago
Select Southwest Airlines flight, departing Tue, Oct 7 from St. Louis to Baltimore, returning Sun, Oct 12, priced at $160 found 18 hours ago
Frontier Airlines
Thu, Oct 9 - Thu, Oct 16
STL
St. Louis
BWI
Baltimore
$164 Roundtrip, found 6 days ago
$164
Roundtrip
found 6 days ago
Select Frontier Airlines flight, departing Thu, Oct 9 from St. Louis to Baltimore, returning Thu, Oct 16, priced at $164 found 6 days ago
Delta
Tue, Oct 7 - Sun, Oct 12
STL
St. Louis
BWI
Baltimore
$167 Roundtrip, found 18 hours ago
$167
Roundtrip
found 18 hours ago
Select Delta flight, departing Tue, Oct 7 from St. Louis to Baltimore, returning Sun, Oct 12, priced at $167 found 18 hours ago

Find the cheapest month to fly from St. Louis (STL) to Baltimore (BWI)

September is typically the cheapest month to fly

From $116 - $541 per traveler.

Graph displaying average flight prices per month

Flights from St. Louis (STL) to Baltimore (BWI)
Origin airport
Lambert-St. Louis Intl.
Destination airport
Baltimore Washington Intl. Thurgood Marshall
Airlines serving
American Airlines, Delta, Frontier Airlines, Southwest Airlines, Spirit Airlines, United
Roundtrip price
$138
Distance
735 mi
Average flight time
3 hours 34 mins

St. Louis to Baltimore Flights

The cheapest times to fly from St. Louis to Baltimore

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from St. Louis to Baltimore are during the month of October. You can find some of the cheapest flights from St. Louis to Baltimore with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from St. Louis to Baltimore

Sunday is one of the best days to book for cheap flights from St. Louis to Baltimore: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from St. Louis to Baltimore

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from St. Louis to Baltimore in 2025. You can also book with separate airlines for your outbound and return journeys, from $68 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap St. Louis to Baltimore flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your St. Louis to Baltimore airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI) cost?
Cheap round-trip flights from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI) start at $197. This information is based on the cheapest price found on Expedia for this return journey departing within the next three months. This airfare is for a Southwest Airlines flight leaving STL on August 1 2025 and touching down at BWI. The price was last updated on July 6 2025 and has not changed since.
What is the cheapest month to fly from STL to BWI?
The cheapest flights from STL to BWI are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
Which airlines fly direct from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
You can fly directly from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI) on a Southwest Airlines flight.
What is the cheapest airline that flies from STL to BWI?
With prices starting from $99 for a one-way flight from STL to BWI, Southwest Airlines is currently the cheapest airline for this route. This fare is based on the lowest price found on Expedia departing within the next three months. The flight takes off from STL on September 18 2025. Prices were last updated on July 6 2025 and have not changed since.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
With an average of 2 nonstop flights departing from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI) every day, you'll be on your way in no time.
What are the most popular departure times for flights from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
Flights between STL and BWI tend to be busiest at 6 AM. If you're after a more relaxed experience and possibly cheaper prices, look for a time when demand is lower.
What day of the week has the most flights from STL to BWI?
Friday has the most flights from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI). Consider traveling on this day and you'll have a greater chance of finding a schedule that works for you.
What is the earliest flight from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
Lambert-St. Louis Intl. Airport (STL)'s earliest flight to Baltimore Washington Intl. Thurgood Marshall Airport (BWI) leaves at approximately 5:35AM UTC-6. With a total travel time of 2h 5m, you'll touch down at around 8:40AM UTC-5.
How long does it take to fly from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
Flights from STL to BWI have an average travel time of 1 hour and 59 minutes. The distance between these two airports is 740 mi.
What is the best time to fly from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
To avoid possible delays on the Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI) route, aim to fly before 3 PM. Later flights have a 22% higher chance of cancellation.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports do you fly into for Baltimore from Lambert-St. Louis Intl. Airport (STL)?
Hop on a direct flight from Lambert-St. Louis Intl. Airport (STL) to Baltimore and you'll land at any one of these hubs:

  • Ronald Reagan Washington National Airport (DCA)
  • Washington Dulles Intl. Airport (IAD)
  • Baltimore Washington Intl. Thurgood Marshall Airport (BWI)

Is it cheaper to buy a plane ticket from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI) last-minute?
Booking your ticket from STL to BWI shortly before your trip is generally more expensive. However, if you're flexible with your travel dates and times, you could score a cheap last-minute fare.
Is it cheaper to book a STL to BWI flight and hotel package?
Compared with arranging flights and hotels separately, booking a STL to BWI flight and hotel package with Expedia could lead to significant savings. Better yet, having everything in one convenient place will take the stress out of planning your trip. Just secure your flights and select from our wide range of hotels, then tailor your trip with other add-ons like tours and car rentals.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
Generally, it's possible to reschedule or cancel your STL to BWI flight. However, if the booking was made more than 24 hours ago, additional charges may apply. Refer to your airline's policies in your itinerary to see what changes are possible and whether any costs are involved. You'll also find more information on our Customer Service portal.

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*Available to One Key members.